It has long been known that a vacuum is a good insulator. Accordingly, vacuum insulation panels are utilized in a variety of insulation environments, especially those applications which demand enhanced thermal performance in a limited space. By way of example, refrigerator manufacturers increasingly are using vacuum insulation panels to insulate refrigerators in view of the more stringent energy standards in the U.S. and abroad that now must be met.
Typically, vacuum insulation panels include powders or granules of a low-density material such as silica. Under conventional methods of making the panels, the low-density powder is dried and placed into a porous inner bag or container. Pressure is applied to the powder-containing inner bag in order to compact the powder into a rigid board. The compacted inner board is then inserted into an impermeable outer envelope which is evacuated to a desired pressure to form a vacuum therein and sealed.
A significant problem with conventional approaches for making the vacuum insulation panels is that it has proven to be very cumbersome and relatively expensive to prepare and configure the panels for the specifications of each commercial end product (e.g., refrigerators) in which the panels are used. In this respect, even different products of the same type, such as refrigerators, require a large number of quite diverse panel sizes and shapes. In particular, two different general approaches have been attempted for satisfying the many different panel configurations required for different end products. In a first approach, the panels are produced and supplied from a single panel producing facility. This first approach, however, suffers from very high distribution and inventory expenses associated with accommodating the vast diversity in panel sizes and shapes required for different manufacturers. For example, equipment used to prepare the panels usually must be re-configured every time panels for a different product are prepared.
A second approach entails production of the panels directly at the end product (e.g., refrigerator) manufacturing sites. This second approach has also been unsatisfactory because of the difficulty in transporting large volumes of the low-density powders or granules (e.g., silica). In addition, the end product manufacturers are generally ill-equipped to handle and process the powder, nor do many manufacturers want to take on this added burden.
From the foregoing, it will be appreciated that there is a need for a vacuum insulation panel and a method of preparing the same in which a broad range of differently shaped and sized panels can be prepared with relative ease, even by the end product (e.g., refrigerator) manufacturers. It is an object of the present invention to provide such a vacuum insulation panel and a method of preparing the same.